The major project in the laboratory is to determine the pathogenetic mechanisms involved in the development of plasmacytomas in BALB/c mice. Plasmacytomas are induced by the intraperitoneal injection of pristane; their formation depends upon the genotype of the host (BALB/c and NZB inbred mice are susceptible); the chronic inflammatory process initiated by the phagocytosis and containment of pristane and by the generation of internal mutagenic substances emanating from the chronic inflammation (oxygen and lipid radicals). The work involves: 1) the identification of genes that determine susceptibility and resistance to plasmacytoma development through the construction of congenic pairs of mice; 2) a study of the inflammatory process to identify biologically active factors in plasmacytomagenesis (growth factors, mutagens), and 3) a detailed study of the histopathogenesis of plasmacytomas to determine the time and site of origin of the chromosome 15 translocations and the progressive changes in plasma cells leading to the autonomous state (proliferative focus development).